The present invention relates to an endoscope shaft in accordance with the preamble of claim 1.
Endoscopes are instruments especially for exploring hollows or tube-shaped conduits of the body, especially for medical purposes. Especially endoscopes for exploring the esophagus, the stomach, the duodenum from the stomach, the intestine from the anus, the urethra, the vesica and the ureter have become known. Such an endoscope is equipped with a lighting device at its front end and with an optical system for visually detecting the area located in front of the body hollow or body canal to be explored. While until recently the optical information detected in front of the front end of the endoscope has been usually transmitted by means of fiber optics through the endoscope towards its operating end behind, the insertion of a camera chip at the front end of the endoscope as well as the electric image transmission and the illustration of the obtained optical information on a monitor constitutes the latest prior art now.
Furthermore, endoscopes usually comprise a so-called working conduit through which various working instruments can be introduced and operated. For example, small-forceps for taking tissue specimens, biopsy needles, heated cutting wires, small scissors, coagulation electrodes or the like are introduced so as to perform surgical measures at the affected tissue, if need be. Finally, as a rule, a fluid conduit for wash and operating wires for bending the front end of the endoscope in various directions are provided. These operating wires are guided through individual conduits within the endoscope shaft towards the front or distal end thereof so as to bend it three-dimensionally by up to 160xc2x0 in the opposite direction of the endoscope shaft.
In this connection essential problems arise now, especially with respect to the tactical feeling which is given to the operator during the bending process. Therefore, there is the danger that, when the intestine is explored, the intestine wall is injured during the bending process of the distal end. Furthermore, it must be possible to be able to exactly position the distal end in the area to be explored and to be treated, if necessary, which requires a sufficient flexibility as well as at the same time a sufficient stiffness, after the predetermined bending position had been reached.
In view of these problems, it is the object of the invention to provide a construction for a distal end portion of an endoscope shaft, said construction ensuring a sufficient flexibility as well as a sufficient stiffness, when the predetermined bending position has been reached, and furthermore giving a sufficient tactical feeling to the operator. According to the present invention, this object is achieved by an endoscope shaft comprising the features of the enclosed claim 1.
Accordingly, the invention consists in forming the distal end portion of a plurality of bellow-shaped bodies or swelling bodies longitudinally juxtaposed and/or stacked, two of which at a time are located diametrically with respect to each other and form a body layer and two longitudinally directly adjacent pairs of bodies of which at a time are phase-shifter by 90xc2x0. Hereby a construction is obtained in which the individual swelling bodies seen in the longitudinal direction are alternately arranged at twelve and six o""clock according to the one layer and at three and nine o""clock according to the neighboring layer. In this way it is possible to achieve a bend-off of the distal end into the intended direction by correspondingly operating the bellows having the same angular position, when they are swelling or contracting, wherein, when the predetermined angular position of the distal end has been reached, the swelling bodies are virtually frozen in this position and thus the fixing of the distal end is maintained.
It has turned out to be particularly advantageous to form the swelling bodies as hydraulically or pneumatically operable bellows according to subclaim 3, whereby a simple and less expensive mode of operation is rendered possible, for instance, by a correspondingly formed pressure medium source, for instance, in the shape of a hand pump giving a sufficient tactical feeling to the operator.
Further advantageous embodiments of the invention are the subject matter of the other subclaims.